Eidos is an ancient philosophical term; loosely speaking, it means the information that makes up an object we then perceive through the material world. When we see something – for example a chair – we see the manifestations of it’s properties – we see wood, four legs, we can even estimate weight, height, velocity, and thousands of other conceptual variables we cannot see. Eidos is where all those variables are defined. The material manifestation directly effects Eidos – if you kick a chair, you suddenly add directional acceleration to it, and you may even – depending on it’s properties of durability – break it into different objects.
The opposite – the altering of somethings properties in Eidos effecting the material form – as it turns out, is also true. This is what we call | Magic.